Power mechanism for typewriting machines



May 2, 1950 R. D. DODGE POWER MECHANISM FOR TYPEWRITING MACHINES Filed June 5, 1947 .WN 0 R0 Y &m @Qsm 6mm wmw mu m 0 m0 m I V0 T g. 0 QM W! M o w mm x 4 wm mm 1 a W 5 0 B Q 1 7 mm MN 4 0% \m k 0 NQN N 9 mm Q ,QN &

Patented May 2, 1950 31 35? rowna MECHANISM FQR- 'rlrrnwnrrmo MACHIEES W Ronald D. Dodge, Poughkeepsim-N. assignor to International Business Machines Corporation; New York, N.Y.; a corporation of New York i a cn We? 1. se ia lie, .5.

Claims 1 This invention relates to typewriting machines.

The primary object of the present invention is to provide an improved means of adjusting the blow of the typefbars imparted by the type bar operating mechanism of a power operated typewriter. An object is to provide a'blowf adjusting rneans vWhich is individual 'to each type bar and which is readily accessible to the servicemen.

Anotherobject is ,to provide a blow adjusting means'which is simple in construction and requires a minimum ofparts.

Other objects of the invention will be pointed out in the following description and claims and illustrated in the accompanying drawings, which disclose, by way of example, the principle of the invention and the bestmode, which has been contempl'ated, of applying that principle. "Iri'the drawings:

Fig; 1 is a vertical section through the power mechanism of a typewriting machine embodying thepresent invention. W

Fig. 2 is a detail- View in section showing one of the power units in operated position.

The numeral l ii'designates one of the lreylevers of which there is one for each'character printing type bar andwhich is pivoted ona cross rod ll suitably supported in the base I 2 of the machine. Each key lever [U is provided with a finge'r b'ut ton Illa and a restoring spring i; which'u'rges the key lever it in a counterclockwise" direction (-Fig. 1). The forward or right hand ends ofthe key levers I G are guided in slots 14a in .a key guide bail l4 which is adjustably .pivotally mounted in the base l2 by means of studsi, only one of which is shown in Fig. -1.

Associated with each key lever ID is a character printing type bar as which, as usual in the art, may be provided with two types lfia comprising upper and lower case characters. The type bars it are supported in a-type basket which includes the usual se m l1 and e pe ba re pivoted in the segment :1 by the usual curved pivot wire IS. The segment l-Tis slotted to ac commo e h ty e b r a s n e he 9s.- ment iscurved, the type bars [6 recline at the angle shown in Fig. 1 but at different levels in the machine.

Each type bar I6 is operated by a power unit which includes a sub-lever I9 connected by a link .to an extension I61) formed in the associated type bar 16, whereby the rocking of the sub-lever I 9 clockwise, through the link 20, actuates the .type bar l-B'in a counterclockwise direction to enga e one .or the .other of the type characters lfiofwith the work sheet on the usual platen Zl.

(Cl. 1971j1) th right oflthe stud 3 lb and to a" lug 1907f the .iiieinber 3 I".with.'the swarm at the r to i bribe en a eme 9 i1 6 l g 2 the type striking through the usual ribbon. At the pririnhgpomt th't pes are guided by'l tyife arden which is secured to the front faceo'r tnseg'm nt n; The type guide zzals snciaoiy supports a ribbon Vibrator '23which' is mounted'dn the upper end of a 11111524 pivoted at itslQtvr one to a tavern for actuating the ribbon vibrator. Any suitable means may be 'usear r'actuanng'the fi bqg W: r "The loweren'd of each sub-lever i9 is formed with" a d ep some [9d which coo erates withfa fulcrum strip Z6 having a" rounded nose 'Zfidand thenotch 19a is kept "seatd' on the nose'rca By means of a sprmgzi which is'agnchored tongs lower endoi the sub-lever 19 below mention I 91; a lu' g ifib in the fulcruinstripifi. "'The spring 21 not only serves to hold" th'e'sub-lever s on the pivot 'r nose 26a, butlalso tends toresltqr'ef'the' ubrlvc Whe h i n, d as'herea fter described and incidentall ass tsin restoring" :the'type bar it after it has Ja e ' Each powe unit in ude a So w !-,-s1 peg! cain'el'eme'nt 28 pivoted at on the sub lhis cam 28 isprovide d' witha res ring spring 29' which anchored to an ar "Z8 in the c m 35 anew alug'struck 'frorn .I'S he c n is provided wi h a sa 2811 des to coopera e t he we which rotates continually in the directio th' ne (Fig. '1) While the "machine is n N mally, however, the upper end of the 281i clears the power'roller '3 0 with the Darts in the position of Fig. 1 which is tlrle flpt- .mal position.

cam 28 has an elongated tail piece 28c w an "ordinarily is hld'iniengagemcnt witH'a 3m in the release member 3:, ,the' spring-31s in .theposition of pig; 1 holding the tail p .6 25a against thelug" 3l a.' The release ineinberflfis provided with a slot "through which'passes 1a stud tib carried by an arm forming partoffth sub-lever i l9. A spring 32; connected t'oan ear to med in the release member 3| just below to the arm of lever "ie'ca'rr mg' tud" '3lli hand 51 o the slo n em er and j l normally holds member 31 up against the his line rnemher 3 ;I, has a lug 310 which justcl a ho e ten i n or e W ts ee e t ephetec le r i de ess h me beroflwill be rocked slightly count g lug Me. This rocks the cam 28 slightly clockwise suiiiciently to bring the upper end of the tread 23b into engagement with the surface of the power roller 33. Thereafter, the power roller 3!] drives the cam 28 in a clockwise direction and, due to the eccentric shape of the tread 28b on member 28, pushes the stud I91) to the right in a short arcuate path, thereby actuating the sublever [9 in a clockwise direction on pivot 26a and, through the link 23, operating the type bar It to effect an imprint from one of the types lea.

If no means is provided to control the blow of the type bars I6, the power roller will actuate the cam 28 until the end of the tread 28b is reached which will occur before the type bar l6 actually strikes, and due to momentum the sub-lever l9 will be carried a little further beyond the point of disengagement of the cam 28 from the power roller 33 by the force of inertia stored in the type bar and the power unit which includes 26 are mounted edgewise on the flat under-face of a transverse frame member 33 which is secured at its ends in the base l2 and the strips 26 are spaced from each other at their left hand ends, adjacent the noses 26a by slots 33a formed in the frame member 33 which also serve to space apart the sub-levers I9, the fulcrum strips 26 being shaped at their left hand ends to the right of the nose 26a so as to project partly into the slots 33a. At their right hand ends the fulcrum strips 26 are spaced by slots formed in a comb spring plate 34 secured to the top of the frame member 33 which is formed with a longitudinal rib 33b for this purpose.

The comb strip 34 has a vertical comb portion 34a spacing the fulcrum strips 26 apart and is also formed with a horizontal comb including the spring prongs or fingers 34b which are slightly bent and extend approximately horizontally directly underneath the nose portion 280 of the cam members 28, each cam member having associated with it a spring prong or finger 34b. Each finger 35b is spring-biased downwardly into engagement with a screw stud 35 which may be turned by means of a screw driver to raise or lower the prongs 341) so as to bring them closer to or further away from the nose portions 280,

as desired. The fulcrum strips 26 are clamped in their adjusted positions by nuts 35a and a clamping strip 330 having holes for the screw studs 35.

In the course of the rotation of the cam 28 by the power roller 30, the nose portion 280 will engage the associated finger 34b and prevent further clockwise rotation of the cam 28 as shown in Fig. 2. Bearing in mind that the stud [9b travels in an arc of a circle toward the right, the cam 28 will be caused to have a motion of translation to the right which will carry it out of engagement with the power roller 30, notwithstanding the fact that an intermediate portion of the tread 2% may, at that moment, contact the power roller 33. It is quite clear from Fig. 2 that by turning the stud 3550 as to raise or lower the prong 34b the point at which the cam 28 leaves the power roller may be regulated very closely.

It is also possible to adjust the clearance between the cam 28 and the power roller 30 individually for each power unit. It is for this purpose that the fulcrum strips 26 are adjustable longitudinally and to facilitate such adjustment they are frictionally clamped in place by a channel-shaped clamping bar 36 and interposed between the edges of the fulcrum strips 26 and the bar 36 is a resilient strip 31 which may be composed of a fairly dense flexible plastic, the channel-shaped bar 38 being attached to the frame member 33 by means of clamp screws 38.

In order to adjust any one of the fulcrum strips 25, the nuts 3511 on both sides of the selected strip 26 are loosened and the strip pushed to the left or pulled to the right the required distance. Notches 260 formed in the ends of the strips 23 enable a suitable hook tool to be engaged with the strip to pull it to the right.

There are a number of reasons why it is desirable that the power units be adjustable to vary the blow. One reason is that the area of type face varies widely, as between a period type bar, representing one extreme, and an upper case M or W, representing the opposite extreme. Another reason is that the type bars are on different levels and, in most commercial machines, the sub-levers must be of different lengths to avoid wide variation in angularity of the connecting links or to reach the cam slots formed in the type bars of some machines.

One of the advantages of the adjusting means described herein is their simplicity. Another advantage of the means comprising the screw studs 35 and fingers 34b is that the point of disengagement may be adjusted to be very precise and the wear on the tread of member 28 at the point of disengagement is spread over a large area and notconcentrated at a very small area as is usually the case with power mechanisms of the snatchroll type. In fact the spring 29, the resiliency of the usual rubber covering of the power roller 30 and the inertia of the train of connections including the type bar assist in producing a snappy disengagement with little slippage and the element 28 is not gradually forced off the power roller.

While there have been shown and described and pointed out the fundamental novel features of the invention, as applied to a preferred embodiment, it will be understood that various omissions and substitutions and changes in the form and details of the device illustrated and in its operation may be made by those skilled in the art without departing from the spirit of the invention. It is the intention, therefore, to be limited only as indicated by the scope of the following claims.

What is claimed is:

1. Power mechanism for typewriters and the like comprising a power roller, a cam supporting member, a cam pivoted thereon and adapted for rolling engagement with the power roller, means for imparting a forward swinging movement to the cam upon its pivot to cause it to engage the power roller for rotation b the latter, means tending constantly to swing the cam in the reverse direction for restoring said cam after disengagement from the powerroller, and an element engaged by said cam in its rotation by said power roller for terminating its rolling engagement with said power roller.

2. Power mechanismfor typewriters and the like comprising a power roller, a cam lever, a segmental cam pivoted on the cam lever, keyoperated means for imparting a forward swinging mavementi. to: thelcam to.- cause. it. to engage. the powenrollier ior rotation by. said roller, means toiswing-thei cam inthe reverse-direction upon disengagement: from thepowerroller, and means engageablewith said cam during; the course of its. rotation by said power roller for disengaging saidicam from-said roller andxenablingthesecond.

named-1 swinging means. to restore. said cam.

13; Power. mechanism for typewriters land. the likacomprising a power: roller, a cam lever, a segmental .campivotedlon the-cam lever and.pro..-.. uid'edi witnanabutment, an actuating member adapted: to. engage said abutment and; imparta forward. swinging. movement vito the cam to. causeit to engage the roller, means.- for swinging the camv .reuersely when disengaged from the roller, and means engageable with said abutment to disengage said cam from said power roller and ren er he. reverse swinging means e fective.

4. Power mechanism for typewriters and the like comprising a power ro1 ler, a cam lever, a segmental cam pivotally mounted on said lever and provided with an abutment, a key lever, an interponentoperable by said key l v r and'p voted o thecam. lever ina posi to p h agains said; abutment when the key- .lever is actuated, whereby a forward swinging movement is imparted to the cam to engage the cam with the power roller for rotation. by the latter, a spring for swinging the cam. 1161615615", and means engascazble. with said. abutment. for positively disengaging said cam from said power roller to enable said spring to restore said cam, said means being adjustable to vary the duration of rotation of the cam by said power roller.

5. A power mechanism for typewriters and other ofiice machines comprising a power roller, a rockable member, a cam element pivoted on said member and rotatable for driving engagement with said power roller, means to initially rotate said element until it is gripped by said power roller and rotated thereby, means to restore said element upon disengagement of said element from the power roller, and means engaged by said element during the course of its rotation by the power roller for disengaging said element from said power roller.

6. A power mechanism for typewriters and other office machines comprising a power roller, a pivoted member having a connection to a device to be operated; a coupling element pivotally mounted on said member and having a tread portion engageable with said power roller by an initial pivotal movement of said element on said member, said coupling element having a release portion; means to impart said initial pivotal movement to said element, and means engaged by said release portion during the course of rotation of said element by the power roller for posi-- tively releasing said tread portion from said roller.

7. In a power mechanism for typewriters and the like, a power roller; a power unit including a member rotatably engageable with said power roller for driving engagement with the latter and means to restore said member after disengagement from said roller, means for imparting an initial rotational movement to said member to engage it with the power roller, and. adjustable means for limiting rotation of said member by the power roller and at the same time rendering the restoring means eiiective.

8. A power mechanism for typewriters and the like comprising, a power roller; a power unit having an element rotatably engageable with the power rollen and a; rockable. support. for said elea. merit, said. element. normally having a .cleara .c&. with respect. tothe said powenrol'ler,saidsuppopt. having afulcrum notch; afulcr-um elementhaue; ing a fulcrum nose seated in said notch, aspring. for restoring said rockable support and holding. said notch in cooperation with said nose and meansto adjustably movably mount the fulcnnnt element to enableadjustment ofsaid clearance.

9. A power mechanism for typewriters and the like comprising-a power roller; apower unit; having an element rotatablyengageablewithgthe power rolleranda. rockable support for said. 81.6.1... ment, said support having afulcrum portioninfulcrum bar having-"pivotal engagement with. the fulcrum portion, a spring for holding said ,-f*u1. crum --portion in pivotal engagement withthe, fulcnum bar, and means to adiustably slidablst mount said fulcrum bar.

1Q. A power mechanism comprising. a power roller, va rockable. support having an operating: connection to a part to be operated, a coupling; element pivoted .on said support for rotating: engagement with the power roller, a key having a projection, and an interponent pivotally and slidably mounted on said support between. said; keyprojection and said .couplingelement anddise, posed so that when the key: is depressed theinterponent is roclged on its pivot to rock said ecu; piing. element into engagement with the powee roller and, when said hey lsheldin operated cone. dition, said interponent will be caught by the key lug during restoration of the rockable support and be prevented from moving between said lug and said coupling element.

11. A power mechanism for typewriters and the like comprising a power roller, a cam unit having a cam rotatable by the power roller and means to initially engage the cam with said roller, means to compel disengagement of the cam from said roller at a predetermined point in the oper ating cycle of the cam unit, and means to vary the point at which the last named means disengages said cam from said roller.

12. A power mechanism for typewriters and like machines comprising a main power roller; power units operable by the power roller, each power unit including a coupling element initially rotatively engageable with the power roller for rotation by the latter and including a support rocked by said rotation of the coupling element; a support frame having a series of guide slots, one for each support; a series of fulcrum bars, one for each support. for pivoting said supports in said slots; restoring springs individual to said supports for maintaining the pivotal relation between the supports and bars; a spring guide comb having a series of slots in alignment with the first named slots for holding said bars in edgewise spaced relation on said support frame and also having a series of prongs in the plane of said coupling elements and operative to disengage said elements from said power roller at various points in the operating cycles of said power units, clamping means for adjustably securing said bars in said slots including screws for adjusting said prongs, and selectively operable means for initially rotating said coupling elements to engage the latter with the power roller.

13. A power operated typewriter having a power roller; a series of power devices operable by the power roller, each power device including a rockable member; a frame, a series of fulcrum members, each having a fulcrum bearing on one of said rockable members; means for mounting said fulcrum members on said frame for individual adjustment of the fulcrum point of each rockable member, and springs individual to said rockable members for maintaining bearing contact between said fulcrum members and said rockable members.

14. A power mechanism for the type bar of a typewriting machine, comprising a power roller; a rock lever having an operating connection to the type bar; an L-shaped cam pivoted on said lever intermediate the ends of said lever and intermediate the ends of one bar of the L, the other bar having a tread portion engageable with the-power roller for partial rotation by the latter, said tread portion being eccentric to the pivot of said cam on said lever whereby to rock said lever and actuate the type bar when the cam is rotated by the power roller, said cam normally having a clearance with the power roller closed by a small initial rotation of the cam to engage the tread portion with the power roller; a fulcrum member having a loose contact pivotal engagement with a portion of said rock lever, a spring for maintaining said pivotal engagement and restoring said lever, means to adjustably movably mount the fulcrum member for adjustment of said pivot, and means to effect said initial rotation.

15. A power mechanism for the type bar of a typewriting machine, comprising a power roller; a rock lever having an operating connection to the type bar; an L-shaped cam pivoted on said lever intermediate the ends of said lever and intermediate the ends of one bar of the L, the other bar having a tread portion engageable with the power roller for partial rotation by the latter, said tread portion being eccentric to the pivot of said cam on said lever whereby to rock said lever and actuate the type bar when the cam is rotated by the power roller, said cam normally having a clearance with the power roller closed by a small initial rotation of the cam to engage the tread portion with the power roller; means engageable with the free end of the bar of the L which is pivoted to said lever for disengaging the cam from the power roller, and means for effecting said initial rotation.

RONALD D. DODGE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,602,757 Dorsey Oct. 12, 1926 1,614,475 Hokanson Jan. 18, 1927 1,661,710 Thompson Mar. 6, 1928 FOREIGN PATENTS Number Country Date 102,337 Austria of 1926 552,797 Great Britain of 1943 

